Abstract

Atmospheric pressuredielectric barrier dischargeplasma is produced in airflow by applying nanosecond high voltage pulses with peak voltage about 35 kV and rising time about 40 ns on a plate-to-plate electrode arrangement. The effects of airflow rate (0–50 m/s) on the discharge characteristics are investigated under different barrier conditions (the bare anode case and the bare cathode case). For both cases, the breakdown voltage and the time lag increase distinctly and the discharge intensity decreases sharply when the airflow rate increases from 0 to 30 m/s, and then keep almost constant until the airflow rate is further increased to 50 m/s. For the bare anode case (the cathode is covered by dielectric plate), the discharge mode transforms gradually from filamentary to diffuse discharge with the increasing airflow rate. While for the bare cathode case, some micro-discharge channels are still excited, though the discharge becomes more diffuse when the airflow rate is higher than 30 m/s. By acquiring the time-resolved images of the discharge, it is proved that it is the primary discharge which becomes diffuse when airflow is introduced and the following two discharges of the same voltage pulse occur principally at the positions where the primary discharge is more intense. And in both cases, the plasma temperatures are reduced, but the degree is different. All the phenomena can be explained mainly by the variation of the space charge distribution when the airflow is introduced into the discharge gap. And it is indicated that the bare anode case has an advantage in obtaining diffuse discharge.

This work was supported by the National Natural Science Foundation of China under Grant No. 51437002. The authors would like to thank Professor X. Wen for his help on the ICCD camera.

Article outline:I. INTRODUCTIONII. EXPERIMENTAL SETUP AND MEASUREMENTIII. RESULTS AND DISCUSSIONA. The electrical characteristics of the nanosecond pulsed DBD in airflowB. The visualization of the nanosecond pulsed DBD in airflowC. The plasma gas temperature of the nanosecond pulsed DBD in airflowIV. CONCLUSION